"Estuaries such as Long Island Sound are among the most valuable ecosystems in the world. The Sound supports diverse marine life, including most of the fish and shellfish we value as food ..."

– Connecticut Sea Grant

Conservation & Research

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Long Island Sound Fun Fact

Long Island Sound is 113 miles long, 21 miles wide (at its widest) and holds about 18 trillion gallons of water. Its average depth is 63 feet – which is just a little deeper than the height of our IMAX screen! Can you fathom that?!

fiddler crab

Common Name: Atlantic marsh fiddler crab

Latin Name:  (Uca pugnax)

Size/weight: A small crab whose body (or carapace) is about 1 inch across. Males are slightly larger than females and have a blue spot on the top center.

Range:  Cape Cod down to northern Florida. This is the most common species of fiddler crab on the U.S. East Coast.

Habitat: in the intertidal mud of salt marshes. The crabs dig burrows, which they use for resting, mating, safety and hibernating. (They are known to roll up a ball of mud to plug their burrow hole at high tide.)

Diet:  They eat the mud too – well, they eat the tiny bits of fungus, algae, microbes, decaying plant & animal matter, and other organisms in the mud. What they don’t digest is deposited back as little mud balls.

Predators: Herons, gulls and other birds; raccoons; blue crabs; and other marsh predators.

Description:  Olive-brown in color. Dark banded walking legs. Slender eye stalks. Fiddler crabs are easily identified by the males, which have one ridiculously large yellowish claw – an adaptation that developed to help them attract females. A bigger claw gets the girl. The large claw, called the chela, can be either the male’s left or right. Also, males have a blue spot on the top center of their carapace.

Note:  Because all their digging helps to aerate the marsh, fiddler crabs are great for a marsh’s health.

Why are they called fiddler crabs? When a male feeds, the back-and-forth movement of its small claw (from the ground to its mouth) near its large claw resembles the motion of someone moving a bow across a fiddle.

Fiddler crabs are very skittish and retreat quickly to their marsh burrows. If you don’t want to go marsh-muckin’ in search of fiddler crabs, you can find them in The Maritime Aquarium's Salt Marsh Gallery.